Apparatus for making photoprints



y 14, 1940- w. H. MORGAN APPARATUS FOR MAKING PHOTOPRINTS Filed May 20,1958 2 Sheets-Sheet l INVENTOR W/Zerf May Z ATTORNEYS May 14, 1940. w.H. MORGAN APPARATUS FOR MAKING PHOTOPRINTS Filed May 20, 1938 2Sheets-Sheet 2 M @IIU M w MB-MM INVENTOR M/bcrf hf Alwyn/z BY A WNEYS kPatented May 14, 1940 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to apparatus for making photoprints.

More particularly stated, the invention relates to apparatus for makingprints on sensitized paper from negatives which may consist of aphotographic film, a negative print or a paper to be copied, such as aletter, check, etc.

Many photoprinting machines now in use are provided with a glass platebetween the light or 0 lamps and the negative. A platen is provided forpressing and holding the sensitized print paper in contact with thenegative and for holding the negative in contact with the glass plate.Unless the paper is in perfect and complete contact with the negativeand the negative is in perfect contact with the glass plate, air pocketswill be formed and the print will be blurred and imperfect. It isparticularly difficult to obtain perfect contact due to variations inthe thickness of materials used and to the use of guides or masks.

In apparatus of the character described, it is also essential that meansbe provided for adjusting the lamps angularly and toward or from theglass plate through which the light is transmitted.

This invention has for its salient object to provide printing apparatusof the character specified having a platen so constructed and arrangedas to prevent the formation of any air pockets and to insure perfect,contact between the sensitized print paper and the negative and betweenthe negative and the glass plate.

Another object of the invention is to provide a platen so constructedand arranged that the sensitized paper will be first engagedsubstantially at the center and then will be successively engagedradially or laterally from the center outwardly, thereby forcing out allair between the print paper and the negative and between the negativeand the glass support upon which it is mounted.

Another object offthe invention is to provide a platen with a surface soconstructed that the sensitized paper will be frictionally engaged andheld against slipping or sliding movement as the platen is engagedtherewith and clamped in closed position.

Another object of the invention is to provide means operable when theplaten is closed and locked in closed position for closing the lampcircuit.

Another object of the invention. is to provide in apparatus of thecharacter described, an improved lamp mounting so arranged that thelamps can be adjusted toward or away from the glass supporting plate orcan be angularly adjusted relative thereto.

Further objects of the invention will appear from the followingspecification taken in connec- 5 tlon with the drawings which form apart of this application, and in which Fig. 1 is a vertical sectionalelevation of apparatus constructed in accordance with the invention, theplaten being shown in dotted lines 10 in open position and in full linesin closed position;

Fig. 2 is an elevational view taken at right angles to Fig. 1;

Fig. 3 is an enlarged sectional elevation taken 16 substantially on line33 of Fig. 1;

Fig. 4 is a top plan view, partly broken away, of the platen;

Fig. 5 is a fragmentary view showing a corner of the platen and detailsof the friction surface;

Fig. 6 is an enlarged sectional elevation of a part of the platen; and

Fig. '7 is a. diagrammatic view showing a wiring diagram of the lampcircuits.

The invention briefly described consists of 26 photoprinting apparatus,including a lamp cham ber or cabinet in which the lamps are verticallyand angularly adjustable and having a glass supporting plate at theupper end thereof through which the light is transmitted and on whichthe 30 negative and sensitized paper are supported during the printingoperation. There is hinged to the top of the cabinet a platen comprisinga frame or support and a pneumatic paper engaging cushion or surface.The pneumatic cushion com- 35 prises a closed pneumatic chamber in whichair is forced through a suitable valve and a friction surface carriedthereby and engageable with the outer surface of the sensitized paper.The cushion and paper engaging surfaces are so 0 formed that when theplaten is closed the center of the cushion engages the outer surface ofthe sensitized paper first and as the downward pressure is increased thepaper is engaged laterally or radially from the center by frictionalprojections in the form of a plurality of separate protuberances whichmay have a pyramidal shape. These projections successively engage theouter surface of the print paper and prevent any slippage as the platenis closed and, furthermore, provide for uniform pressure over the outersurface of the print paper and force the paper into complete engagementwith or contact 'with the negative, even where there are variations inthickness and the platen surface engages a mat. or u mask which providesan additional thickness to be compensated for.

The platen is also provided with a switch for closing the lamp circuit,this switch being controlled by the handle which is used to open andclose the platen in such a manner that when the platen is latched inclosed position the circuit is closed and when the platen is unlatchedthe circuit is opened.

Further details of the invention will appear from the followingdescription.

In the form of the invention illustrated in the drawings, there is showna cabinet Ill having a lamp chamber l I, one wall l2 of the cabinetbeing provided with a. hinged door 13 to give access to the chamber Ii.

The bottom I4 of the lamp chamber is provided with a plurality ofopenings I5 in which are mounted spherical bearings or balls l6 throughwhich extend the lamp supporting tubes or posts II.

The spherical bearings or balls I6 are frictionally held in the openingsl5 by pressure exerted by resilient plates l8, this pressure beingcontrolled by bolts l9 and wing nuts 20.

The tubes or posts I l are vertically slldable through the centralopenings in the balls it, but are frictionally held in any desiredvertical position of adjustment by means of circular springs 2| whichare mounted on sleeves 22 carried by the balls l6 and extendingdownwardly therefrom the sleeves being slotted or recessed, as shown at23 and 24, to permit the springs 2| to engage the tubes or posts H. Thewires 25 for the lamps extend upwardly through the tubes H.

The ball bearings l6 permit the lamp to be angularly adjusted in theopening l5 and the tube H can be moved upwardly or downwardly throughthe ball and sleeve 22, being held in any desired position by the spring2|.

A glass plate 30, preferably of opal glass, is mounted above the lamps3| and the top of the cabinet I0 is provided with a top plate or support32 having an opening 33 above the plate 30. A plate 35 is mounted in theopening 33, preferably of plate glass, which forms the support for thenegative 36 to be printed and the sensitized print paper 31.

In order to firmly and securely press the negative and the print paperdownwardly on the glass supporting plate 35, the apparatus is providedwith a platen P which is hinged at 38 to lugs 39 carried by thesupporting plate 32.

The platen P comprises a base or main frame 40 which has secured to itsundersurface a rectangular closed pneumatic bag comprising two sheets 4|and 42 of rubber or rubber composition, which are vulcanized together orclosed at their outer edges, as shown at 43. The outer sheet 4| hasextending therethrough a valve stem 44 of the usual construction, thestem extending outwardly through the frame or platen base 40. Air ispumped through the valve stem and valve into the air chamber formedbetween the sheets 41 and 42 which form the bag and air chamber.

The sheet 42 has cemented or otherwise secured thereto a sheet whichforms the frictional paper engaging surface. This sheet, as shownparticularly in Figs. 4, 5 and 6, does not extend entirely to the edgesof the platen, but has its outer edges spaced therefrom and from thestrips 45 which engage the outer edges of the pneumatic bag to the base40. The sheet 42 has a margin of approximately one-half an inch betweenthe outer edges of sheet 45 and the strip 43, which provides a flexiblemargin and permits the sheet 45 to be pressed flat against plate 35.

The outer surface of the sheet 45 has formed thereon a plurality ofprojections 43 which, in the form of the invention shown, are pyramidalin shape.

The pneumatic cushion is thickest at thelongitudinal and transversecenter thereo! and thus as the platen is closed, the outer surface ofthe sensitized paper is first engaged by the center of the surface orsheet 45. As a downward pressure is increased or continued the outersurface of the sensitized paper is engaged successively from the centerof the cushion and of the friction sheet 45 outwardly. The engagement oithe paper with the projections 43 prevents any tendency of the paper toslip or slide out of position as the platen is closed. Furthermore,since the surface of the sheet 45 is formed with a plurality offrictional projections, a perfect contact between the sensitized paperand the negative and between thenegative and the plate 35 is insured.

The platen base 40 has secured to its outer surface a frame 50, and abell crank lever comprising arms 5l and 52 is pivoted at 53 to the frontend of the frame 50. A handle 54 is formed on the outer end of the bellcrank lever arm ll.

When the platen is in open position the bell crank lever is disposed inthe position shown in dotted lines in Fig. 1, or with the lever arm 5|substantially at right angles to the frame and platen base 40. A stop 55is provided for holding the bell crank lever in this position.

The arm 52 of the bell crank lever has pivoted thereon at 56 a latch 51,one end of which is engaged by a spring 58 which tends to swing thelatch in an anticlockwise direction. A hook 53 is formed on the lowerend of the latch 51 and is engageable with a staple or eye 50 carried bythe top plate 32 of the cabinet I.

Means is provided in connection with the bell crank lever for openingand closing the lamp circuit for the lamps 3|. This means consists of aswitch S mounted on the platen frame 40 and having an upwardly extendingarm 6| which is connected by a flexible connection or wire 82 to thebell crank lever arm 52. When the switch arm 5| is in the dotted or dashline position shown in Fig. 1, the lamp circuit is open.

To close the platen the handle 54 is engaged by the operator and theplaten is swung downwardly with the bell crank lever in a positionsubstantially at right angles to the platen frame. After the platen hasreached its lower position and pressure has been exerted thereon, thebell crank lever is swung to the position shown in full lines in Fig. 1,engaging the hook 59 with the eye or staple 80. As the bell crank leveris thus swung in an anticlockwise direction on its pivot 53, the cord orwire 82 will pull the lamp switch arm 6| from the dotted line to thefull line position shown in Fig. 1, thus closing the lamp circuit.

When the print has been made the bell crank lever is swung intoclockwise direction, releasing the hook 59 from the eye 60 and at thesame time permitting the switch arm 6| under spring pressure to move tothe open position shown in dotted lines in Fig. 1.

The lamp circuit is shown diagrammatically in Fig. 7. In this figure thepower lines or mains are shown at and l I. The main control switch 12 isprovided for connecting the power lines to the lamp circuit. From theswitch 12 the circuit passes to wires 13 and 14. Two pilot lights,designated; R and W, are mounted in the chamber I I, one of these lightsbeing red and the other white. The circuit for the pilot light R passesfrom the wire 13 through a wire 15 to the lamp R and from the lamp backthrough a wire 16 to the wire 14. The wire I5, has a switch 11 mountedtherein.

The circuit for the lamp W passes fro-m wire 13 through a wire 18 andswitch 19 to the lamp W and from the lamp .back to the wire H through awire 80. I

Any desired number of lamps may be mounted in the lamp chamber H and inthe wire diagram there are shown eight lamps A, B, C, D, E, F, G and H.

The main lamp circuit from the wires 13 and 14 extends through wires 8|and 82, connected respectively to the wires 13 and M. The switch S abovedescribed, is mounted in the wire 8| and the switch control arm 8 l ,'asabove described. is controlled by the bell crank lever mounted on theplaten.

Each of the lamps A, B, C, D, E, F, G and, H is connected across thewires 8i and 82 in the manner shown in the wiring diagram, and aseparate switch 85 is provided in each lamp circuit so that any desirednumber of lamps can be utilized. Since the wiring diagram clearly showsthe circuit for the lamps, any further detailed description is notdeemed necessary. It should be noted, however, that in order to closethe lamp circuits through any of the lamps having their switches 85closed, it is necessary to close the switch S.

From the foregoing specification it will be evident that simple,practical and effective printing apparatus has been designed, in whichmeans is provided for vertical and angular adjustment of the lamps, foreffectively preventing air pockets and insuring complete and perfectcontact between the print paper and the negative and the negative andthe glass on which thenegative is mounted, and for insuring the closingof the lamp circuit when the platen is moved to closed position, and theopening of the lamp circuit when the platen is unlatched and swungupwardly to open position.

Although one specific embodiment of the invention has been particularlyshown and described, it will be understood that the invention is capableof modification and that changes in the construction and in thearrangement of the various cooperating parts may be made withoutdeparting from the spirit or scope of the invention, as expressed in thefollowing claims.

What I claim is:

1. In photoprinting apparatus, a support for the negative and sensitizedpaper and. a platen mounted to move toward and away from said support topress the paper and negative intocontact with each other, said platenhaving an inflated pneumatic cushion on the under surface thereof, saidcushion having secured to its-outer surface a sheet of flexible materialhaving projecting therefrom a plurality of uniformly arrangedprojections to frictionally engage the print paper from the center ofthe cushion outwardly to the edges thereof, the outer edges of theflexible sheet being spaced inwardly from the outer edges of thecushion.

2. In photoprinting apparatus, a support for the negative and sensitizedpaper and a platen mounted to move toward and away from said support topress the paper and negative into contact with each other, said platenhaving a cushion on the under surface thereof, the paper engagingsurface having a plurality of uniformly arranged, friction, paperengaging projections thereon, said cushion being thicker at the centerthereof and tapering in thickness from the center to the outer edgesthereof, said projections engaging the paper first at the center andthen outwardly to the edges thereof, thus holding the paper firmly inposition from its first engagement therewith.

WILBERT H. MORGAN.

